Automatic radio tuner



June 6, 1944. s WELLS 2,350,543

AUTOMATIC RADIO TUNER Filed Janj 14, 1943 6 Sheets-$heet l June 6, 1944. s WELLS AUTOMATIC RADIO TUNER- Filed Jan. 14. 1943 6 Sheets-Sheet 2 June 6,1944. A, s, WELLS 2,350,543

AUTOMATIC RADIO TUNER Filed Jan. 14. 1943 e Sheets- Sheet s June 6, 1944.

A. s. WELLS AUTOMATIC RADIO TUNER e Sheeis-Sheet 4 Filed Jan. 14, 1943 June 6, 1944. v A. s. WELLS AUTOMATIC RADIO TUNER Filed Jan. 14, 1943 6 Sheets-Sheet 5 June 6, 1944., A. s. WELLS v 2,350,543

AUTOMATIC RADIO TUNER Filed Jan. 14. 1943 e She'ts-Sheet 6 Patented June 6, 1944 AUTOMATIC RADIO TUNER,

Albert S. Wells, Chicago, Ill., assignor to'Wells- Gardner & Co., Chicago, 111., a corporation of,

Illinois Application January 14, 1943, Serial No. 472,371

30 Claims.

The tuning device of the present invention is designed primarily for use in situations where it is desirable to pick up reports or signals in recurrent sequence from a group of stations transmitted in different frequencies; and in order to successively bring in these stations, provision is made for automatically adjusting the plates of the condenser in each case, and for a predetermined interval, to the required position to bring in the stations in sequential order.

Although the present invention is designed primarily with reference to the automatic operation above described, provision is made for disconnecting the automatic train in order to permit manual adjustment in the usual manner. With the above ends in view, the mechanism is so designed that continuously motor driven means may be successively and sequentially brought into train with the devices which regulate the degree of adjustment of the condenser plates so that in each instance, a regulating movement, at the proper time, and in the required degree will be imparted to the rock shaft which carries the group of condenser plates with the result that for a timed interval the parts will be adjusted to the degree required to attune the apparatus to the frequency of each of the sending stations comprising the group.

Further objects and details will appear from a description of the invention in conjunction with the accompanying drawings, wherein Figure 1 is an exterior perspective view of the tuning apparatus of the present invention;

Fig. 2 is a diagram of the wiring circuits employed;

Fig. 3 is a sectional view through the casing at a point near the right-hand end thereof as viewed in Fig. 1;

Fig. 4 is a similar view taken through the cen ter of the casing;

Fig. 5 is a plan view of the operating mechanism with the casing broken away to reveal the interior;

Figures 6, 7, and 8 are views of the shuttle bar, thrust bar, and adjustable trip mechanism for regulating the throw of the condenser plate rock shaft, showing the parts in successive stages of the operation;

Figures 9 and 10 are perspective views of the vertically movable armature bars which are actuated in sequence to control the setting of the thrust bars;

Fig. 11 is a perspective view of the universal rocking plate for selectively engagingand releasing the armature bars;

Fig. 12 is a composite perspective view of the adjusting block for switching the apparatus from automatic to manual operation; and

Fig. 13 is a perspective view of the latching switch.

The automatic apparatus, as a whole, is housed within. a casing comprising a rear wall [0, end walls H and I2; a front wall I3, which merges into an oblique panel l4, and a top wall or roof 15. Within the casing is located a base plate l6 which supports a frame box of rectangular formation comprising end Walls I1 and I8, a front wall l9, and a rear wall 20. The frame box is provided along its base with a flange 2| which is rigidly secured to the base plate I B. The inner frame box affords a support or framework for most of the mechanism presently tobe described.

The casing stands in adjacent relation to a condenser 22 comprising a set of condenser plates 23 mounted upon a divided shaft 24 which ex tends through the casing from end to end there-.

of, and terminates in a knob .25 provided to permit direct operation in lieu of either the automatic or button control.

The rock shaft, within the frame box, carries a pair of arms 26 which support the ends of a universal swinging bar 21 adapted to be contacted by any one of a series of lugs 28 each carried by a thrust bar 29 normally held in retracted position by a spring 30. Each of the thrust bars is intended to attune the condenser to the frequency of a particular sending station, and the range of movement of each thrust bar will be correspondingly limited by means presently to be described to the tuning requirements of the associated station. The thrust bars are thus in the nature of movement-transmitting elements adapted to variably rotate the rocking shaft to meet individual tuning requirements.

Each thrust bar is provided on its upper edge with a rearwardly pointing finger 3| which overlies a notch or recess 32 open at its rear end to afford clearance for the reciprocation of a constantly operating movement-imparting element in the nature of a shuttle bar 33 which is carried at each end by aplate 34 which lies in sliding abutment against the inner face of the adjacent end wall of the frame box. Each shuttle bar plate is supported and guided by a headed guide stud 35 and a crank stud 36, both of which extend through anadjacent slot 31 in the end wall of the frame box. (See Fig. 3).

The crank studs at opposite ends of the shuttle bar each provide a mounting for a link 38 having its forward end pivoted to a disc 39 on drive pinion .49 on a vertical shaft 50 in train with reduction gear mechanism 5| driven by.

the shaft 52 of a constant speed motor 53 supported upon the base plate l6 near vthe rear. right-hand end of the casing; :(See Fig. 3.)

Referring now particularly to Figure 4 in its relation to Figures 6, 7, and 8, it will be noted that in Fig. 4 the thrust bar there'illustrated is tilted upwardly at the rear end so that the shuttlebar 33 during its constant lateral reciprocations will clear the finger 3| and enter the notch 32, which operation is ineffective to impart movement to the thrust bar. In. Fig. 6 the thrust bar" has been lowered slightly so that the end of the finger 3| lies in the path of movement of the shuttle bar 33 which, however, is here shown in its rearward or retracted position'. Fig., '7 shows the shuttle bar advancing to carry forward the thrust bar and with it the lug 28 which engages the universal swinging bar 21 which in Fig. '7 has been moved forwardly to rock the condenser shaft'zd. It will be noted from Fig. 'L'however,

that the thrust barstill stands in position to engage the shuttle bar which is continuing its advance, which range of movement of the shuttle bar must be the maximum required to attune the condenser plates to each'of'the sending stations of the group. t

It is therefore necessary, ineach instance, that the thrust bar shall maintain contact with the advancing shuttle bar only during the period re-' quired to impart the intended rocking movement to the condenser shaft and shall thereupon be disengaged therefrom bymechanism now to be described. v

Each of the thrust bars has associated therewith an underlying latch bar 54 provided in its upper edge with afnotch 55 having an abrupt rear face 56 which coacts with a'rider lug 51 on theoassociated thrust bar which lug has an abrupt rear face 58 and a beveled'forward face 59 in complementary relation to a'b'eveled forward face 60 of the associated notch.

Near the rear end each latch bar is provided with a guide slot 6| through which is entered a universal supporting rod 62 adapted to sustain the rear ends. of the entire group'of latch rods each of which is individuallyacljustable by means of a screw 63threaded through anear 64 laterally extending from the latch bar. The respective adjustingscrews are carried by a bank of spindles 65 which extend through the forward wall of the framebox and throughthe front wall l3 of thecasing and terminate in a row of adjusting knobs 66, each of which is intended to secure proper attunement with a particular sending station.

- Each spindle immediately-in advance of the threaded stem carries a washer 61 backed by a spring clip 68 bearing against the wall of the frame box. By rotating theindividual knobs 66,- the latch bars can be individually adjusted to bring the respective notch shoulders 56 each to shuttle bar so that the latter will thereupon 7 continue to the limit of its advance without imparting additional movement to the thrust bar. Since the efiective movement of the thrust bar determines the degree to which the condenser shaft will be rocked, the proper amount of movement forfeach sending frequency can be regulated by the individual adjustments imparted to v the "respective knobs 66 comprising the group.

The rear or tail end of each of the thrust bars is-normally held elevated as in Figure 4 by contact with the shoulder 69 forming the lower terminus of a lateral'recess 70 in an associated releasing device which in' the present instance is in the form of an armature bar 1| (or M. as the case may be) which armature bars are equal in number to the number of thrust bars, but in order to compactly arrange the mechanism, the armature bars of the type shown in, Figure 9 are alternated with the type shown in Figure 10.

Each armature bar consists of a section 12 (or 12 formed of magnetic material, a metal section 13 (or 13a) formed of non-magnetic material; and a tail piece 14 provided with an inwardly projecting foot 15. The'armature bar of Fig. 10 also provides an upper extension guide bar 16 which is simply for the purpose of adding the required length. Aside from the slight diiference in detail, the operation of each armature bar comprising the entire group is the same, and the armature bars need not be of the specific form illustrated.

Each of the armature bars has its magnetic section 12nio'unted as the pole piece within a soleth proper position to clear the associated thrust 5 noid coil Tl carried within a frame 18 secured to the'rear wall of the frame box and so arranged that when the coil is energized, the armature bar will be drawn downwardly against the tension of a coil spring 19 hearing against a cap 66 thereby lowering'the shoulder 69 and permitting the rider lug on the associated thrust bar to make contact with the under-lying latch bar which'brings the finger 3| into the path of travel of the shuttle bar so that the thrust bar will be advanced to the required extent upon the next forward reciprocation of the shuttle bar.

1 The armature bar, however, will be drawn down still farther until the foot engages the lower edge of a universal swinging latch plate 8|' (Figures 4 and 11) which is carried by a trunnion rod 82 having its ends journaled within the end walls of the frame box, which trunnion rod is provided with upstanding fingers 83 engaged by springs 84 which normally hold the latch plate in rearwardly retracted position but permit it to be swung for-' staggering the armature'bars of the two different forms, an upper and a lower row of solenoid coils may be employed thus greatly reducing the spacing required for the coils and the frames supporting the same. Each of the armature bars 'I I it acts against the tension of a spring 85 corresponding in function to the springs I9. (See Fig. 10.)

In order to successively energize the respective solenoids at timed intervals which, however, need not be uniform, the following mechanism is employed.

Each of the solenoids is in circuit with an assigned pair of spring switch members 86 and 81 (Fig. 4) which are normally open and the lower switch member is associated with a spring arm 88 carrying a roller 89 adapted to be contacted by a boss 99 on the surface of a constantly rotating timing drum 9| carried by a shaft 92, which constitutes a timing device for selectively and successively energizing the individual solenoids.

The respective bosses are arranged in a spiral row, as shown in Fig. 5, so that each of the switches will be closed by oneonly of the entire series of bosses during a single rotation of the drum.

The shaft 92 at its right-hand end carries a worm wheel 93 meshing with a worm 94 carried by a worm shaft 95 mounting a spur gear 95 in mesh with a driving spur gear 91 on the shaft 4'! so that power derived from the motor will rotate the drum at a relatively slow but uniform rate of speed, thereby in turn bringing the respective bosses 90 into contact with the switch rollers 89 associated therewith so that the switches in turn will be momentarily closed thereby energizing the associated solenoids which draw down the respective armature bars into position to be latched by the universal latch bar 8|. The closing of each switch is but momentary but thereafter the latch bar will function to hold the armature bar in lowered position during a predetermined interval of time and until the next boss of the series makes engagement with the associated switch roller which results in the release of a previously latched armature bar and results in a latching of the second bar.

It is also poss ble to disable the automatic lowering of the armature bars by the rotation of they timing drum, nd to effect a selective lowering of any one of the armature bars by means of the depression of any one of a series of aligned finger button switches 98 located on the face of the panel I4 immediately below a correspondin row of light bulbs 99. The circuit wire which perm ts this operation is shown in Fig. 2 and will be presntly described in detail.

The above may be termed a semi-automatic operation. but it is also possib e to operate the condenser directly by the rotation of the knob 25 at the right-hand end of t e cas ng. This capacity for hand operation is desirable in prel minarily adjusting the positions of the indivi ual trip bars by the turning of the knob 66 so that it i possible to hand adjust the condenser for any particular station until clear reception follows after which the latch bar can be adjusted to a corresponding position.

In changing from hand operation to automatic operation a push rod ID!) is employed. which is entered through guide lugs I8I. 102. I93 on the outer face of the frame box wall H. The push rod carries a collar I84 provided with a bent finger I which engages the lower end of a coil spring I06, the upper end of which is secured to a bent finger IIiI extending obliquely upward from the shaft 24. When the rod IIJII is turned to the position shown inFig. 3, the finger I05 will 0c.-

flanged lug IIB secured to the endwall of the frame box. The inner end of the push rod I00 is adapted to engage a finger III on the trunnion shaft 82. so that as the rod is pushed inwardly, the trunnion shaft will be rocked and the universal plate 8I will release and clear any one of the armature bars which may stand in depressed position. The turning of the push rod to the spring releasin position and the locking of the rod by the engagement of the notch I08 with the spline I09 under the thrust of a spring H2 and the turning of a switch H3 will condition the machine for the semi-automatic operation to be controlled by the depression of the buttons 98 in any desired or timed sequence.

In order to operate the mechanism satisfactorily it is necessary to mute the loud speaker momentarily during the interval required to shift from one station to the next in order to cut out disturbing mechanical or electrical noises and to again bring in the loud speaker after tuning has been effected; and it is also necessary to make provision forshifting the illumination from one light to the next to register with the station next to be attuned. It is also desirable to deenergize the currently operating solenoid after attuning has been effected to prevent overheating during the interval of reception after the necessary tuning adjustment has been secured by the mechanism heretofore described. Provision must also be made for shifting from automatic to button control while at the same time making provision for the continued utilization of all portions of the mechanism which control the tuning to the particular stations in response to the selective control by the buttons rather than by the continuously rotating drum and the electrical means provided for attaining these various results are illustrated in the wiring diagram and will now be described in detail.

In addition to the spiral series of bosses the constantly rotating drum is provided at its left end with a circular series of bosses IM, one for each station, which coact with a roller II5 on a spring arm H6 associated with a lower switch contact II! which when momentarily lifted by the passage of a boss II4 will make closure with a fixed contact II8. This operation will occur as the initiator stage in the tuning shift-from one station to the next and slightl in advance of the closure of the corresponding solenoid circuit by contact of the associated boss with the switch closing roller 89.

The closing of the switch II7I I8 when the circuit is set for automatic operation by the turning'of the control switch II3 to the point A will close a circuit comprisin switch contact I I1, wire I I9, switch I I3, wire I20 to line wire I32 and, from line wire I22 through wires HI and I23 to solenoid coil I24 and return wire I25 leading to switch contact H8. The energizing of the solenoid coil I24 lifts armature lever I26 which is pivoted in its center and causes its inner end to be engaged by pivoted latch I2'I. The opposite end of the lever I26 is drawn down thereby closing a group of relay switch I28 whichconditlons the circuit to be finally closed by the slightly deferred closure of contacts 8186 when actuated by the particular boss 90 'ofthe spiral series which is special to the tuning of the incoming station.

' The relay circuit which includes the switch I28 comprises the following constituents: wire I29, secondary I30 of transformer whose'primary I3I is in circuit with line wires I22 and I32, header wire I33 which is in circuit relation with each or the several circuit assemblies one for each station comprised in the group, lead wire I34 to switch contacts I35I36, wire I31 leading to solenoid 11 and return wire I38 leading back to movable spring switch 81 which is closed by boss 90 special to the circuit assembly in question. The circuit is completed through wire I39, switch II3a, which is movable in unison with H3, and

return wire I40 leading to the relay switch I28.

In preparation for reception from a newly attuned station it is necessary that the momentarily muted loud speaker be restored to service and that the appropriate light be flashed on and the circuits now to be described are provided to attain these results. The switch I35 is formed of a strip of spring metal, the free upper end of which is engaged by and cammed to circuit closing position by the lowering of the end of the associated thrust bar and which is connected with a spring switch member I4I which efiects delayed energizing of an unlocking relay for releasing the latch I21 after a brief interval of time in a manner presently to be described.

The spring switch member I35 when moved makes circuit closing engagement. with contact I42 in alight circuit including wire I43, bulb 99. header .wire I44 to secondary I30 and thence through return header wire I33 and branch wire I34 to switch I35. 7

The unlatching of the pivoted armature I26 and opening of switch I28 which is necessary to restore the loud speaker to service and the means to effect this resultwill now be described. The branch wire I2I leading from line wire I22, leads to the last of a series of contacts I45 on the last of,:the spring: switch arms? I'4I1'3of the respective assemblies. The last. contact" I45 is. normally in closed relation'withthe last "contact I46 on a wire section I41 which carries the next contact I45 at its opposite end and so on throughoutthe remainder of the group thus maintaining a normally closedseries arrangement from end to end.

- When a spring switch member MI is depressed inunisonwith the connected'switch member I35 the circuit is broken at that particular point. Thelast contact I46 connects with a return wire I41 in circuit with" condenser plates I48-,-I49 connected with branch wire I2I. The condenser plates I48-I49 are in circuit with a vacuum tube I50 which in turn is in circuit with an unlocking relay coil I5I whose core when energized serves to momentarily draw up the tail end of the pivoted latch I21 thereby releasing 'the' armature lever I26 which is spring pulled to break 'theswitch contact I28, it being understood thatin the diagram three only of the switches are shown vbut that the number will'correspond to the number of group assemblies comprised in the entire series. The arrangement is such that when any one of the contact switches I45-I46 is opened, and when 'a charge of approximately 3 microfarads builds upin the'condensers. an impulse will be discharged through the vacuum tube which mo-' mentarily energizes the'unlocking relay and unlatches the switch armature I26 after a very brief interval, suflicient, however, to maintain the loud speaker in muted condition during the shift from one station to the next. The circuit to the unlocking coil also includes a rectifier I52 connected with the line wires while the motor 53 is in circuit through wires I53-I54 and switch I54 with the line wires.

The means provided for cutting out the auto matic operation to permit button control will now be described. In order to set the machine for hand operation the switch II3 with its companion I I3a is moved from the positions A indicating automatic to the positions M indicating manual. Thereafter a selected button 98 special to the intended tuning is depressed which operates the connected double switch contacts I55-I55a, which close in unison with contacts I56I56a. The switch contact I55 connects with header wire I51 common to all the assemblies of the series while the switch contact I55a connects with header wire I58. Wire I51 leads to the M side of switch H3, and wire I58 leads to the M side of switch 311. Contacts I56 and I56a are both connected with an extension of wire I38 leading to the solenoid coil 11 and like connections are provided for each assembly throughout the series.

When the switches H3 and 3:1 are moved away from the A positions the automatic circuits actuated by the rotation of the drum 9I are cut out so that the'successive closing of the switches 81-86 by the spiral series of bosses on thedrum is ineffective to produce energizing of the solenoids 11 which latter during button control are selectively energized at the will of the operator and for any period desired. This cutting out of the automatic control occurs since the wire I20 which leads to switch contact II1'is opened by the shifting of the contact II3 to the M position while the circuit including contacts 86-81 is likewise opened.

The following circuit is established when a selected button is depressed and switch I55-I56 is closed from contact I55 through wire I 51 to'M, through switch I I3, wire 120, branch wire I2I, wire I23, coil I24, wire I25, branch header wire I59, common to all the assemblies and through switch contact I56 to I55. The energizing of this circuit by hand control corresponds to the automatic closing of switch II1I I8 by the circular series of bosses II4 on the rotating drum which are ineffective during hand. operation. In the hand operation, however, as in the automatic operation it is desirable that the closing'ofcontacts I55--'I56 should slightly precede the closing of contacts II5aI56a which'energize the solenoids-11 so that the loud speaker will be muted at the beginning of the adjusting operations.

The closing of switch contacts I55aI50aenergizes the solenoids 11 through the following circuit: contact I55a, wire I58 to M, switch IIZla, wire I40, switch I 28, previously closed through the preceding circuit, wire I29, secondary coil I30, wire I34, switch I35I35, wire'I31, solenoid coil 11, wire I38 to contacts I56a--I55a.

The energizing of solenoid 11 draws down the vertical armature bar H and lowers the thrust bar 29 which breaks contacts I35--I36 and contacts I 45-I 46 and closes contacts I 35I42. This closes the light circuit and momentarily energizes unlocking coil I5I, unlatching the switch lever I26 and opening switch I28 to break the grounding of the loud speaker and bring in reception from the selected station for as long a period as is desired by the operator and until another button is depressed which releases the previously latched armature bar l! by the lowering of another bar 11 and thus establishes the same set of operating conditions through another circuit assembly of the series. ton control the operating sequence is in the main identical with that effected automatically save for the fact that the operating sequence and the periods of reception from the various stations are under the selective control of the operator.

The dropping of the armature bar either automatically or by button control will lower the associated thrust bar which will then be advanced by the shuttle bar until it is released therefrom by a notch in the associated trip bar,,

By thrusting in the push button I02 the clearing plate ill will be actuated to release any armature bar which may be depressed, and by turning the rod Hill, the spring I05 will be thrown out of tension so that in these circumstances the hand button may be turned to. any desired degree and the shaft 24, being relieved from spring tension, will maintain any adjustment which may be manually imparted to the condenser shaft.

It is believed that the operation of the device Thus under butwill be clearly understood from the foregoing" description. The mechanism is one which may be employed with all or a portion onlyof the sending stations comprising the complete group by properly positioning the bosses on the timing or variable intervals of any desired period. ,t

The speed of rotation of the timing drum being constant, the reception intervals can be accurately computed and the constant reciprocation of the shuttle bar insures the prompt actuation of any thrust bar which may be released to engage the shuttle bar.

This is insured by reason of the fact that the momentary energizing of one of the solenoids will result in the instant latching of the depressed armature bar which may remain latched during several subsequent reciprocations of the shuttle bar and until a second bar has been depressed to release the first. Furthermore, the fact that the shuttle bar in its advanced position may underlie the line of fingers 3! on the group of thrust bars at the instant when an armature bar is lowered, makes no difference in the operation of the device, since the finger of the released thrust bar even if momentarily arrested by contact with the top of the shuttle bar, will thereafter drop into position to bring its butt end into the line of movement of the shuttle bar as soon as the same is retracted so that on the next advancing movement the end of the finger will be contacted and the thrust bar will be carried forward to the extent permitted by the adjustment of the latch bar.

There is thus no necessity for maintaining a close timing relation between the positions occupied by the bosses on the timing drum and the starting points in the advance and recession of the shuttle bar, although a constant timing relation is maintained between the rotation of the timing drumand the cycles of movement of the shuttlebar since both of these mechanisms are I driven from a single source of power.

The general construction of the mechanism is one which permits the use of metal stampings to be largely employed, and the structure as a whole is one which may be easily and speedily and accurately assembled and which affords means for precise adjustment of the latch bars to secure close tuning to the wave frequently of a multiplicity of stations. Although the invention has been described with particularity it is not the intention, unless otherwise indicated in the claims, to limit the same to the embodiment before described since numerous modifications in structure may be made without departing from the [principles of the invention.

I claim:

1. In radio tuning mechanism the combination of;condenser plates and a movable mounting for the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the movable mounting, o a constantly operating movement imparting element, adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the movement imparting element, timing devices and connections for successively in timed order actuating the releasing devices to permit engagement of a released transmission element by the movement imparting element, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the mounting required in tuning to the variable frequencies of each of a group of transmitting stations.

2. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttle bar adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, timing devices and connections for successively in timed order actuating the releasing devices to permit engagement of a released-transmission element by the shuttle bar, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations.

3. In radio tuning mechanism the combination of condenser plates and a movable mounting for the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the mounting, a constantly operating movement imparting element, adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission element's out of engaging relation with the movegree of. movement to the mounting required in tuning to the variable frequencies of each of a group of transmitting stations, means for disabling the operation of the timing devices, and

individual manually operable devices for selectively operating-the several releasing devices.

4. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttle bar adapted to engage singly with each of the transmission elements, releasing devices for normally liolding'the transmission elements out of engaging relation with the shuttle bar, timing devices and connections for successively and selectively actuating the releasing devices to permit engagement of a released transmission element by the shuttle bar, individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations, means for disabling the operation of the timing devices and individual manually operable devices for selectively operating the several releasing devices.

5. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly. operating movement imparting element, adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the movement imparting element, timing devices and connections for successively and selectively actuating the releasing devices to permit engagement of a released transmission element by the movement imparting element, latching means adapted to engage and hold each of the releasing devices in actuated position until the timed actuation of the next releasing device, and individually adjustable elements for limiting the period of engagement of .each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations.

6. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft,

hold each of the releasing devices in actuated position until the timed actuation of the next releasing device, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations.

'7. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same a group of selectively actuated transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the movement imparting element, timing devices and connections for successively and selectively actuating the releasing devices to permit engagement of a released transmission element by the movement imparting element, latching means adapted to engage and hold each of the releasing devices in actuated position until the timed actuation of the next releasing device, individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each group of transmitting stations, means for disabling the operation of the timing devices, and manual means for actuating the several releasing devices.

8. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttle bar adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, timing devices and connections for successively and selectively actuating the releasin devices to permit engagement of a released transmission element by the shuttle bar, latching means adapted to engage and hold each of the releasing devices in actuated position until the timed actuation of the next releasing device, individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of the group of transmitting stations, means for disabling the operation of the timing devices, and individual manually operable devices for selectively operating the several releasing devices.

9. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttle bar adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, timing devices and connections for successively and selectively actuating the, releasing devices to permit engagement of a released transmission element by the shuttle bar, a swinging universal latch plate positioned to be swung by each of the releasing devices when actuated and to hold the same latched against return until the timed actuation of the next releasing device, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations.

10. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the ma shaft,

a constantly reciprocating shuttle bar adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, timing devices and connections for successively and selectively actuating the releasing devices to permit engagement of a released transmission element by the shuttle bar, a swinging universal latch plate positioned to be swung by each of the releasing devices when actuated and to hold the same latched against return until the timed actuation of the neXt releasing device, individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations, means for disabling the operation of the timing devices, and individual manually operable devices for selectively operating the several releasing devices.

11. In radio tuning mechanism the combination of condenser plates and a rock shaft mountin the same, a group of selectively actuated thrust bars each adapted to impart rotation in variable degree to the rock shaft, a shuttle bar and means for imparting constant lateral reciprocation thereto, a group of releasing devices adapted normally to hold the associated thrust bars out of engagement with the shuttle bar, timing device and connections for successively and selectively actuating the releasing devices to bring each released thrust bar into the path of movement of the shuttle bar, and individually adjustable elements, one for each thrust bar for limiting the period of engagement of the thrust bar, with the shuttle bar to that required in turning the rock shaft to the desired tuning requirements.

12. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars each adapted to impart rotation in variable degree to the rock shaft, a shuttle bar and means for imparting constant lateral reciprocation thereto, a group of releasing device adapted normally to hold the associated thrust bars out of engagement with the shuttle bar, timing devices and connections for successively and selectively actuating the releasing devices to bring each released thrust bar into the path of movement of the shuttle bar, and individually adjustable elements, one for each thrust bar, for limiting the period of engagement of the thrust bar with the shuttle bar to that required in turning the rock shaft to the desired tuning requirements, means for disabling the operation of the timing devices, and manual means for selectively operating the several releasing devices.

13. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars each adapted to impart rotation in variable degree to the rock shaft, a shuttle bar and means for imparting constant lateral reciprocation thereto, a group of releasing devices adapted normally to hold the associated thrust bars out of engagement with the shuttle bar, timing devices and connections for successively and selectively actuating the releasing devices to bring each released thrust bar into the path of movement of the shuttle bar, and a group of individually adjustable latch bars one underlying each thrust bar, each latch bar being configured to afford riding contact for the associated thrust bar to hold the same in engagement with the shuttle bar during a period commensurate with the adjustment of the latch bar.

14. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars each adapted to impart rotation in variable degree to the rock shaft, a shuttle bar and means. for imparting constant lateral reciprocation thereto, a group of releasing devices adapted normally to hold the associated thrust bars out of engagement with theshuttle bar. timing devices and connections for successively and selectively actuating the releasing devices to bring each released thrust bar into the path of movement of the shuttle bar, and a group of individually adjustable latch bars one underlying each thrust bar, each latch bar being configured to afford riding contact for the associated thrust bar to hold the same in engagement with the shuttle bar during a period commensurate with the adjustment of the latch bar, means for disabling the operation of the timing devices, and individual, manually operable devices for selectively operating the several releasing devices.

15. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars adapted to impart rotation individually in variable degree to the rock shaft, a constantly operating movement imparting element adapted to engage singly with each of the thrust bars, releasing armature bars, one for each thrust bar adapted normally to hold the thrust bars out of engagement with the movement imparting element and adapted when actuated to bring the associated thrust bar into engagement therewith, a solenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associated thrust bar, individually adjustable devices, one for each thrust bar, for variably timing the periods of possible engagement of the individual thrust bars with the movement imparting element, a constantly operating timing device, circuit connections for each of the solenoid coils, and switches positioned to be operated selectively and successively by the timing device.

16. .In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars adapted to impart rotation individually in variable degree to the rock shaft, a constantly operating movement imparting element adapted to engage singly with each of the thrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out of engagement with the movement imparting element and adapted when actuated to bring the associated thrust bar into engagement therewith, a solenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associated thrust bar, individually adjustable devices, one for each thrust bar for variably timing the periods of possible engagement of the individual thrust bars with the movement imparting element, -a constantly rotating timing drum provided on its periphery with variously positioned bosses one for each solenoid coil, circuit connections one for each solenoid coil, and switches one in each circuit positioned in the path of movement of an associated boss and adapted to be actuated thereby to energize the associated solenoid,

all. In radio tuning mechanism the combina- ,tion of condenser plates and a rock shaft mounting the same,v a group of selectively actuated thrust bars adapted to impart rotation individually in variable degree to the rock shaft, a constantly operating movement imparting element adapted to engage singly with each of the thrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out of engagement with the movement imparting element and adapted when actuated to bring the associated thrust bar into engagement therewith, asolenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associated thrust bar, individually adjustable devices, one for each thrust bar, for variably timing the periods of possible engagement of the individual thrust bars with the movement imparting element, a constantly operating timing device, circuit connections for each of the solenoid coils, switches positioned to be operated selectively and successively by the timing device, and a universal latch bar adapted to engage and latch each of the armature bars when actuated and hold the same latched until the actuation of thenext armature bar.

18. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars adapted to impart rotation individually in variable degree to the rock shaft, a constantly operating movement imparting element adapted to engage singly with each of the thrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out of engagementwith the movement imparting element and adapted when actuated to bring the associated thrust barinto engagement there with, a solenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associated thrust bar, individually adjustable devices, one for each thrust bar, for variably timing the periods of possible engagement of the individual thrust bars with the movement imparting element, a

constantly rotating timing drum provided on its periphery with variously positioned bosses, one for each solenoid coil, circuit connections one for each solenoid coil, switches one in each circuit,

positioned in the path of movement of an associated boss and adapted to be actuated thereby to energize the associated solenoid, and a universal latch baradapted to engage and latch each of the armature bars when actuated and hold the same latched until the actuation of the next armature bar.

19, In radio tuning mechanism the combina tion of condenser plates and a rock shaft mount ing the same, a group of selectively actuated thrust bars adapted to impart rotation individually in variable d gree to the rock shaft, a constantly operating movement imparting element adapted to engage singly with each of the thrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out of engagement with the movement imparting element and adapted when actuated to bring th associated thrust bar into engagement therewith, a solenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associated thrust bar,

individually adjustable devices, one for each .thrust bar, for variably timing the periods of possible engagement orthe individual thrust bars 5 5' wit hIthe,..movement imparting element, a constantly operating; timing device, circuit connections for each of the solenoid coils, switches positioned to beoperated in timed order and successively by the timing device, a universal latch bar adapted to engage and latch each of the armature bars when actuated and hold the same latched until the actuation of the next armature bar, disabling means for preventing the timed energizing of the solenoids, and individually manually operable switches and circuit connections for selectively energizing the respective solenoids.

' 20.,In radio tuning mechanism th combina tion of condenser plates and a rock shaft mountingthe same, a group of selectively actuated thrust, bars adapted to impart rotation individ- .ually'in variable degree to. the rock shaft, a constantly operating movement imparting element adapted to engagesingly with each of the thrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out ofengagement with the movement im arting element and adapted when actuated to bring the associated thrust bar into engagement therewith, a solenoid coil surrounding each armature .bar and adapted when energized to draw the and latch each of the armature bars when actuated and hold the same latched until the actuation of the next armature bar, disabling means for preventing the timed energizing of the solenoids, individually manually operable switches and circuit connections for selectively energizing the respective solenoids, and means fordisabling said circuit connections to permit direct manual adjustment of the rock shaft.

21..In radio tuning mechanism the combination'of condenser plates and a movable mounting for the same, a group of selectively actuated transmission ,elements each adapted to be brought into operative engagement with the movable mounting, a constantly operating movement imparting element, ,adapted to engage singly with each of the transmission elements, releasing devices for normally holding the trans- .mission elements out of engaging relation with the movement imparting element, means for actuating the releasing devices to permit engagemnt of a released transmission element by the movement imparting element, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree or movement to the mounting required in tuning to the variable frequencies of eachpf a group of transmitting stations. 22; In radio tuning mechanism the combination of condenser plates and a movable mountingfor the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the movable'mounting, a constantly operating move- 1ment imparting element, adapted to engage singly with each ofthe' transmission elements,

releasing devices for normally holding the trans mission elements out of engagingrela'tion with the movement imparting element, means for actuating the releasing devices to permit engagement of a'releas'ed transmission element by the movement imparting element, and individually adjustable elements for limiting the period ofengagement of each transmission element toimpart the degree of movement to themounting required in tuning tothe variable frequencies of each of a group of transmitting stations, and automaticmeans for cutting out the tuning efi'ect during periods of adjustment and-restoring the effect thereafter: p Y

23. In radio tuning mechanism the combinationof condenser plates and a rock shaft mounting the same, a group o'f selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, aconstantly, reciprocating shuttle bar adapted toengage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, means 'for actuating the releasing devices to permit engagement or a released transmission element by the shuttle bar, and individually adjustable elementsfor limiting the period of engagement of each transmission element to impart tiredegree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations.

24. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttle bar adapted to engage singly with each of the transmission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, means for actuating the releasing devices to permit engagement of a released transmission element by the shuttle bar, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations, and automatic means for cutting out the tuning effect during periods of adjustment and restoring the efiect thereafter.

25. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttle bar adapted to engage singly with each of the trans mission elements, releasing devices for normally holding the transmission elements out of engaging relation with the shuttle bar, means for actuating the releasing devices to Permit engagement of a released transmission element by the shuttle bar, latching means adapted to engage and hold each of the releasing devices in actuated position until the tim d actuation of the next releasing device, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tun ing to the variable frequencies of each of a group of transmitting stations.

26. In radio tuning mechanism th combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated transmission elements each adapted'to be brought into operative engagement with the rock shaft, a constantly reciprocating shuttlebaradapted to engage singly with eachof the transmission elements, releasing devices for-normally holding the transmission elements out of engaging relation with the shuttle bar, means: for actuating the releasing devices to permit: engagement of a released transmission element by the shuttle bar, latching "means-"adapted to engage and hold each of the releasing devices in actuated position until the timed actuation of the-next releasing device, and individually adjustableelements for limitin-g the period of engagement of each transmission element to impart thedegree of movement to theroek Shaft-req uiredin tuning to the variable frequeneiesor eacho ia group of transmittin'g stations, and automatic means for'cu-t ting out the tuning effect during periods of: adjustment and restoring the eifect thereafter.-

27. In radio 'tuning' mechanism the combination of condenser plates 'and'a rock shaft-mounting the same, a group of selectively actuated trans-mission elements each ad'aptedto be brought into operative engagement with thero'ck' shaft, a constantly reciprocating shuttle bar adapted to engage singly each of the transmission elements, releasing devices for nonnany hold-ing the transmission elements out of engaging relation with the shuttle bar, means for actuating the releasing devices to permit engagement of a released transmission element by the shuttle bar, a swinging universal latch plate positioned to be swung by each of the releasing devices when actuated and to hold the same latched against return until the timed actuation of the next releasing device, and individually adjustable elements for limiting the period of engagement of each transmission element to impart the degree of movement to the rock shaft required in tuning to the variable frequencies of each of a group of transmitting stations.

28. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars each adapted to impart rotation in variable degree to the rock shaft, a shuttle bar and means for imparting constant lateral reciprocation thereto, a group of releasing devices adapted normally to hold the associated thrust bars out of engagement with the shuttle bar, means for actuating the releasing devices to bring each released thrust bar into the path of movement of the shuttle bar, and a group of individually adjustable latch bars one underlying each thrust bar, each latch bar being configured to aiiord riding contact for the associated thrust bar to hold the same in engagement with the shuttle bar during a period commensurate with the adjustment of the latch bar.

29. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same, a group of selectively actuated thrust bars adapted to impart rotation individually in variable degree to the rock shaft, a constantly operating movement imparting element adapted to engage singly with each of the thrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out of engagement with the movement imparting element and adapted when actuated to bring the associated thrust bar into engagement therewith, a solenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associated thrust bar, individually adjustable devices, one for each thrust bar; for variably timing the periods-of possible engagement of the individual thrust bars with the movement imparting element, a constantly operating timing device, circuit connections for each of the solenoid coils, switches positioned to be operated in timed order and successively by the timing device, a universal latch bar adapted to engage and latch each of the armature bars when actuated and hold the same latched until the actuation of the next armature bar, disabling means for preventing the timed energizing of the solenoids, and individually manually operable switches and circuit connections for selectively energizing the respective solenoids, said switches and connections including means for cutting out thecircuit connections operated by: the timing ,device and including means for timing the energizing of solenoids at the will of theoperator. 1 g

30. In radio tuning mechanism the combination of condenser plates and a rock shaft mounting the same; a group of selectively actuated thrust bars adapted to impart rotation individually in variable degree ;to the rock shaft, a constantly operating movement. imparting element adapted to engage singly with each of thethrust bars, releasing armature bars, one for each thrust bar, adapted normally to hold the thrust bars out of engagement with the movement impartin element and adapted when actuated to bringthe associated thrust bar into engagementtherewith, a solenoid coil surrounding each armature bar and adapted when energized to draw the same into position to release the associatedthrust bar; individually adjustable devices, on for each thrust bar, for variably timing the periods of possible engagement of the individual thrust bars with the movement imparting element, a constantly operating timing device, circuit connections for each of the solenoid coils, switches positioned to be operated in timed order and successively by thetiming device, a universal latch bar adapted toengage and latch each of the armature bars when actuated and hold the-same latched until the actuation of the next armature bar, disabling means for preventing the timed energizing of the solenoids, and individually manually operable switches and circuit connections for selectively energizing the respective solenoids, and circuit means and electrically operated devices for cutting out the tuning efiect during periods of adjustment whether eflected automatically or manually and adapted to automatically restore said tuning effect after a timed interval of readjustment. I i I a ALBERT S. WELLS.- 

